Feeding of sheets



mei'

a X LL Du C n e P... e fTI .DU X E 2 5 Z UR AX 12 01 22 8 OP 5.1 2F

Oct. 31, 1939. R. F. s. HoLNEss FEEDING OF SHEETS Filed July 19, 1938 3 Sheets-Sheet 1 ing 25o. RADIANIt Oct. 31, 1939.

Cross Reference R. F. G. HOLNESS FEEDING 0F sHEI-:Ts

Filed July 19, 1938 3 Sheets-Sheet 2 Examne Gross Reference Filed July 19, 1938 3 Sheets-Sheet 3 lso Patented Oct. 31, 1939 UNITED STATES PATENT OFFICE FEEDING OF SHEETS Application July 19, 1938, Serial No. 220,118 In Great Britain July 30, 1937 22 Claims.

This invention relates to the feeding of sheets, for multi-colour printing and other purposes in which a sheet has to be positioned accurately for feeding.

In the known automatic sheet-feeding devices, correct positioning of the sheet is accomplished by bringing two contiguous edges of the sheet up to stops. It is usual to trim these two edges previous to use so that they are exactly at right angles. By this means satisfactory register is obtained in multi-colour printing involving more than one printing operation provided that the humidity of the paper remains fairly constant.

In certain processes the humidity of the paper varies and this is particularly so in forms of intaglio printing in which the paper is deliberately damped before use. This results in a marked dimensional change for which allowance is made when making the printing surfaces. Unfortunately this change of dimension varies somewhat from sheet to sheet, making exact register by the: ordinary mechanical means impossible. If the! sheet were registered by mechanical front and side lays in the usual manner, the variations of register would increase progressively from the junction of the trimmed sides to the opposite corner and thus, for this particular purpose the known type of automatic sheet feeder is useless.

Heretofore in practice these damped sheets have had to be fed by hand. They are provided with lay marks near to the centre of the sheet and the machine is provided with an equal number, usually two, of reference points to which the sheets are set by eye. By this means the variation in dimensions between any sheet and the standard is distributed evenly about the centre'of the sheet, thus reducing the maximum amount by which two printings fail to register to under one half of that which would result if the sheets were positioned by their edges.

Up to the present no automatic method of feeding sheets to lay marks and not edges has been used.

The present invention has for its object to provide an improved method and means for accurately positioning sheets to lay marks instead of edges whereby the greater accuracy in registration secured by the usual hand-feed method referred to may be attained in a fully automatic manner enabling a higher rate of output to be achieved in any process in which feeding of the sheets to lay marks is necessary in order to secure effective results.

The term colour printing used herein includes any process in which a sheet receives more than one impression other than on a multi-colour machine employing a single impression cylinder.

According to the present invention, in a method of feeding sheets wherein the sheets are registered to lay marks thereon so that any error in registration due to humidity or other cause is distributed about a predetermined point on the sheet, the registration of the sheets is effected by automatically positioning the sheet to lay marks thereon by means under the control of photosensitive devices influenced by the said lay marks.

'Ihe invention also includes a method of feeding sheets provided with lay marks from a pile to an impression cylinder for colour printing, wherein during feeding of the sheets into position for engagement by the impression cylinder grippers, each sheet is positioned by means controlled by photo-sensitive devices influenced by the said lay marks.

The invention furthermore includes a method of feeding sheets in register to an impression cylinder for colour printing which comprises providing the sheets with lay marks arranged in two lines that intersect at registration points centrally located on the sheets, and operating sheetshifting and positioning means under the control of photo-sensitive devices inuenced by the said lay marks. The registration point need not be at the geometrical center of the sheet, and the term centrally located is to be understood as applying generally to any position that is substantially spaced from the edges of the sheet.

The invention furthermore includes a method of feeding sheets from a pile which comprises effecting pre-registration of the sheets to an edge or edges by usual mechanical means including front and/or side lays and thereafter automatically registering the sheets to lay marks thereon by the use of mechanism under the control of photo-sensitive devices arranged to be influenced by the said lay marks.

Preferably each sheet is provided with three lay marks in two intersecting lines substantially at right angles to the edges of the sheet, two of such lay marks being in one line transverse to the direction of travel of the sheet, and the third lay mark being arranged in a line disposed in the said direction of travel, and automatic registration is effected under the control of three photo-sensitive devices positioned for operation by the said lay marks.

The invention also includes apparatus for carrying out the methods referred to comprising photo-sensitive devices, sheet-shifting and positioning mechanism, and means including electrical relays under the control of said photosensitive devices for operating said sheet-shifting and positioning mechanism.

The invention is hereinafter described by way of example with reference to the accompanying diagrammatic drawings, in which:

Figure l is a plan view of a sheet provided with lay marks;

Figure 2 is a perspective view illustrating feeding and registration apparatus according to the invention;

Figure 3 is a diagram of the electrical circuit for the apparatus shown in Figure 2;

Figure 4 is a fragmentary plan view illustrating an alternative means for arresting movement of a lay bar under control of a photo-sensitive de v1ce;

Figure 5 is a fragmentary side elevation corresponding to Figure 4; and

Figure 6 is a diagram showing the circuit arrangement of the photo-sensitive device and its associated equipment,

Each sheet I is, as shown in Figure l, provided with three lay marks, 2, 3, 4. In order to attain the object of laying to the centre 5 of the sheet, these lay marks are printed so as to lie in bisecting lines substantially at right angles to the sides of the sheet, two lay marks 2, 3 being in one line at right angles to the direction of travel indicated by the arrow, and the third lay mark 4 being in the other line lying in the direction of travel and preferably adjacent the rear edge of the sheet. The lay marks may be arranged in lines intersecting at any other desired point in the sheet, for instance, the centre of a design on or to be impressed on the sheet, in order to distribute any error in registration about the said point as symmetrically as possible.

For the purpose of removing the sheets one by one from a pile 6 and carrying the same towards the grippers 'I on the impression cylinder 8, any known form of mechanism may be used.

As shown in Figure 2, three illuminating systems 9, IIl, II are associated respectively with three photo-sensitive devices I2, I3, I4 arranged to be energised by passage of the respective lay marks 2, 3, 4, in relation thereto.

When a sheet is delivered to the laying-on board, tapes or other devices used for carrying the sheet to the laying-on position, it may be travelling slightly out of square. 'Ihe two photosensitive devices I2, I3 are placed so that when both are operated by the respective lay marks 2, 3 a sheet will be correctly positioned with regard to travel towards the laying-on position. The devices I2, I3 operate electro-magnets I5, I6 controlling grippers I'I, I8 respectively, while the device i4 operates an electro-magnet I9 or other device to arrest movement of a transverse lay bar 20. Thus, when all three photo-sensitive devices I2, I3, i4 have been operated by the respective lay marks 2, 3, 4, the sheet will be correctly positioned for feeding to the impression cylinder and any error that there may be in registration due to unequal expansion or contraction of the sheets will be distributed equally about the centre 5 or other preselected point.

In the apparatus shown in Figure 2, the photosensitive devices I2, I3, I4 are operated by transmitted light and for this reason transparent windows or plain openings 2Ia, 2lb, 2Ic respectively are arranged in the board 2I. The illuminating systems 9, It), II and the photo-sensitive devices I2, I3, I4 are movably mounted on rods preferably with screw or micrometer adjustment in order Y from the shaft 28 which is tted with a sprocket 28a driven by chain 29 from a sprocket 3U mounted on a shaft of the feeder.

When the sheet I is in the correct position for feeding to the impression cylinder 8, the lay marks 2. 3, 4 will each cut oiT or substantially reduce the illumination incident on the respective photo-sensitive device I2, I3, I4. This change is utilised in lmown manner to operate the relays 3|, 32, 33 (Figure 3) through amplifiers I2a, I3a, I4a respectively. For these relays 3I, 32, 33, it is preferred to use grid-controlled vapour discharge tubes owing to their extremely rapid operation.

If the sheet arrives with the lay marks 2, 3 out of square one mark, e. g., the mark 2, arrives at the photo-sensitive device I2 first causing its associated relay 3l to close. This energises the coil I5 causing the gripper IT to drop and hold one edge of the paper to the transverse lay pull bar 20. Simultaneously, the operating coil 22c of the relay 22 is energised closing contacts 22a, 2217. The closing of the contacts 22h supplies power to the operating coil 22e through either or both the switch 35 and the rotary contact device 2B so that if either of these is in the closed position the relay 22 remains closed despite the opening of contacts 3I. At the commencement of the operation, the switch 35 is open and the contact device 26 is closed. The action of tapes, two of which 36, 31 are shown as being driven by rollers 38. 39, causes the sheet to turn about the gripper I'I. When the line joining the lay marks 2 and 3 becomes parallel to the axis of the impression cylinder of the printing machine, the lay mark 3 energises the respective photo-sensitive device I3 operating relay 32 which energises the coil I6 causing the gripper I8 to hold the sheet, effectively preventing further travel with relation to the transverse lay bar 20. Simultaneously the coil 23o of the relay 23 is energised closing contacts 23a and 23h. The contacts 23h function in like manner to the contacts 22b of the relay 22 to prevent de-energising of the relay 23 on the opening of the relay 32, provided that either contacts 2S or 35 are closed. Both contacts 22a and 23a are now closed and thus power is applied to the relay 33 which previous to this had been unable to operate and thus was unaffected by the passage of any part of the design on, or the edge of, the sheet I over the photo-sensitive device intended to co-operate with the lay mark 4.

The operation of a cam 4I now causes the transverse lay pull bar 20 to travel in the direction of the arrow under the influence of spring 20a, the bar 20 carrying the sheet I with it. When the sheet is correctly positioned for feeding, the lay mark 4 operates the photo-sensitive device I4, closing the relay 33 and energising the coil I9 t-o prevent further motion of the bar 20. This effect may be secured, for example. by using an insert 23h of magnetic material in the bar 2D or making the bar 2D of magnetic material to co-operate with a xed electro-magnet with the known magnetic chuck.

I'he positioning of the sheet is now complete and it is ready to be fed into the press but there will in general be a short interval of time before the impression cylinder grippers 1 are in the correct position to receive the sheet. During this period the sheet is held stationary but the cam 4 I, which is driven from the press, continues to travel causing slack in the link mechanism associated therewith, whereby a spring 42 is able to separate the lever 43 from the cam roller carrying arm 44 and thereby effect closing of the switch 35.

During the whole of the preceding operations the rotary switch 25, which, like the switches 26 and 21, is coupled mechanically to the printing mechanism, is arranged to maintain the current supply to the relays 3| and 32. At the instant that the impression cylinder 8 is ready to receive the sheet I the switch breaks the circuit to relays 3| and 32 and their associated coils I5 and I6, raising armatures I1 and I8 and thus freeing the sheet to be gripped by the grippers 1 of the impression cylinder 8. At this time the switches and 26 are closed. Thus the relays 22 and 23 are maintained closed, keeping the relay 33 and its associated coil I9 energised, thus preventing the release of the transverse lay bar 20, and obviating sudden movement of the same or of its associated mechanism and sudden stopping thereof when the slack previously mentioned is taken up. This motion, apart from its detrimental effect on the mechanism, would tend to move the position of the sheet while being engaged by the grippers 1 and would impair the accuracy of the lay. Rectifying devices 22d, 23d, are inserted in the leads from the relays 3|, 32 to the relay coils 22o, 23C, so that when the relays 3|, 32 open, the coils I1, I8 are not maintained energised by current from the contacts 22h, 23h.

Durirg the positioning process, the rotary switch 21 has been supplying current to the coil of the relay 24, thus maintaining contacts 46 closed. The contacts 46 are arranged on opening to trip the feeder and/or press and may be, for example, in series with the no volts coil of the starter of the electric motor driving the printing press. At the instant of or just prior to the opening of relays 3| and 32 to allow feeding of the sheet, the rotary switch 21 breaks the circuit from the contact 21a and connects the coil 45 of relay 24 through contact 41 to the junction of the relay 33 and the coil I9. If for any reason any of the preceding operations should not have been properly performed and hence the sheet I not be properly registered, then one or more of the contacts 22a, 23a or 33 will be open and the current to the coil 45 of relay 24 will be interrupted causing the apparatus to stop. However, if all operations have been correctly performed, contacts 22a, 23a and 33 will be closed and will maintain the current on the relay 24 and the machine will continue to operate. Very shortly after, this switch 21 returns the coil 45 direct to the input of the power line so that the current supply to relay 24 is not interrupted when the coil I9 is de-energised. Should the trip mechanism function, a restart, after clearing the fault, can be secured by a switch 48 to short-circuit the rotary switch 21 or by a mechanical device acting to hold the contacts of relay 24 closed until normal operation is resumed. A rectifying device 41a may be inserted, as shown, to prevent any possii t'ross Heierence coils I9 operating in the manner of the wellbility of the switch 21 supplying current direct from the positive lead to energise the coil I9.

The sheet I is now gripped by grippers 1 of the impression cylinder 8 and is taken into the printing press.

The cam 4| continues its revolution and at about the limit of its travel the rotary switch 26 opens leaving circuit continuity dependent on the switch 35. On its return half revolution when the cam 4| has taken up the slack in its associated link mechanism, the switch 35 is opened and cuts off the current to the relays 22 and 23, and thus opens the contacts 22a, 22h, 23a, 23D and relay 33, thereby resetting this part of the mechanism and releasing the grip on the bar 28 without causing jar in the mechanism and also allowing the cam 4| to restore the bar 20 to the starting end of its stroke for another operation. Shortly after the switch 35 has opened, the rotary switch 26 short-circuits it again to supply current to this part oi the apparatus for the next operation.

The rotary switch 25 is arranged so as not to supply current again to the relays 3| and 32 until after the leading edge of the next sheet has passed the photo-sensitive devices I2 and I3 to eliminate any chance of faulty action due to the change in illumination on them at the instant they are passed by the edge of the sheet.

Resistance capacity absorbers 49, 50 may be inserted, as shown in Figure 3, to minimise sparking at the switch contacts.

It may be desirable to arrange for a previous mechanical alignment of the sheet, for example, to one edge, or to two adjacent edges at right angles, to reduce the extent of the movement required by the part of the apparatus controlled by the photo-sensitive devices. This mechanical alignment may be performed in known manner and is particularly advantageous when dealing with damp sheets of paper which render it diificult to secure a properly knocked up stack, i. e., a stack in which two adjacent edges of each sheet are in the same two intersecting vertical planes.

Previous mechanical alignment also permits simple arrangements for the feeding when desired of sheets not bearing lay marks when accurate register is not required, e. g., when socalled waste sheets are fed during the adjustment of the printing press.

As shown in Figure 2, the sheets fed from the pile 6 by mechanism of the usual form are brought up to front lays 5| 52 and a side lay bar 53 is then caused to move, the spring nger device 53a gripping the sheet and pulling it up to a side lay 54, thus eiecting mechanical registration of the sheet by its edges. The sheet is then ready for registration to lay marks as before described and the front lays 5|, 52 are caused to lift and release the sheet which travels down the board 2| on the tapes 36, 31.

An alternative method of arresting the longitudinal movement of the bar 28 makes use of the principe of the roller clutch, as shown in Figures 4 and 5. Two rollers 55 and 55 are mounted with their axes vertical one on either side of the bar 20 the guides 51, 58 of which are recessed, as shown, to provide an opening for each roller, the opening being less than the roller diameter at one end and greater at the other. Springs 59 and 60 tend to press the rollers towards the narrow end of the openings but a stronger spring 6| acting through a lever 62 pivoted at 62a prevents this occurring. Adjustable stops which are not shown limit the travel of lever 62 to the very small amount necessary either to keep the rollers out of simultaneous contact with bar and the guides 51, 56, or to release the rollers sufficiently for them to make this simultaneous contact. 'Ihe energising of the coil I9 actuates the armature I9a so as to move the lever 62 to release the rollers 55, 55 which thereupon, under the inluence of the springs 59, 60, grip the bar 20, which is moving in the direction of the arrow (Fig. 4).

The coil I9 is maintained energised during the travel of the cam 4I away from the bar 20 and also on the return stroke so that the release of the bar 20 is eiected by the cam 4I taking up the slack in its associated link mechanism and finally applying pressure to the bar 20 when it automatically frees itself despite the fact that coil I9 is still energised. The switch 35 can be omitted in this arrangement and the rotary switch 26 arranged to break circuit continuity for a very short period at the end of the return stroke of the bar 20, thus de-energising the relays 33, 22 and 23 and resetting the mechanism for the next operation.

The photo-sensitive device and its associated equipment may be identical for each of the three sets used and the arrangement thereof is wellknown per se. The arrangement shown in Figure 6 is for operation from a D. C. source which must be different from that of the rest of the apparatus. The photo-sensitive device I2, I3 or Il; may be a photo-cell of the emissive type either vacuum or gas filled and may incorporate amplication by secondary emission from target electrodes in known manner, if desired, the electrodes and subsidiary apparatus for producing this latter result not being shown. Further, the photo-sensitive device in this circuit arrangement may bc of the photo-conductive type such as, for example, a thin film of selenium spread on glass between gold electrodes as described in British Patent No. 284,942. In each case the photo-sensitive device can be regarded from the point of view of circuit operation as a resistance the value of which decreases on illumination.

As normally arranged, i. e.y with lay marks darker than and/or more opaque than the paper, the photo-sensitive device suffers a decrease of illumination on being acted on by its lay mark. Thus, its resistance is increased and the potential difference between the earthy line and the junction of the lead to the photo-sensitive device and to the resistance 63 is increased. This positive pulse is passed by the condenser 64 to the grid of the three-electrode valve 65 which amplifies it and causes it to appear in its anode circuit as a negative pulse which is passed to the primary of the transformer 66. The secondary is so connected that this is applied as a positive pulse through the resistance 61 to the grid of a rid-controiled vapour or gas discharge tube, i. e., the relay 3|, 32 or 33. The resistance 6'I is inserted to limit grid current during the conductive period of the relay 3l, 32, 33. For the anode potential applied to it the slider of resistance 68 is adjusted so that the grid is suflciently negative with respect to the cathode to keep the tube normally in a non-conducting state. When the positive pulse arrives, however, this negative bias is overcome and the tube becomes conducting and is no longer controllable by its grid electrode, i. e., it remains conducting until the anode circuit is interrupted. Resistance 69 and condenser 'l0 are for decoupling the supply to the photosensitive device and the resistance 'II and condenser '12 serve the same function for the anode supply to the valve 65. The resistance 'I3 is the grid leak providing a conducting path from grid to cathode of the valve 65 and the resistance 'I6 provides negative grid bias, the resistance 'I5 and condensers 15a, 16a acting as decoupling devices in known manner. -Resistances 'VI and I8 form a potential divider across the supply, the earthy" line being connected to their junction, thus enabling negative grid bias for relay 3l, 32 or 33 to be obtained by adjustment of the slider on the resistance 68. A choke coil '.'9 and condenser 80 serve to remove irregularities from the supply.

It will be understood that the invention is not limited to the particular embodiment hereinbefore described and that the sheet-shifting and positioning mechanism controlled by the photosensitive devices may be modied in various ways. For exampley at the point where the electro-magnetic grippers hold the sheet to the transverse lay bar, the said bar may be provided with rotatable parts in order to facilitate the swinging of the sheet about one or other of such grippers as herein described. Furthermore, the grippers themselves may be fitted with swivel end portions or may be otherwise rotatable.

The photo-sensitive devices may be operated by reflected light and the photo-sensitive devices and/or the illuminating systems may have suitable lens systems associated therewith. The lay marks, instead of being darker or more opaque than the material of the sheet, may be lighter or less opaque, in which case each lay mark will increase the illumination on the associated photosensitive device and the circuit connections thereof will be suitably modified.

What I claim and desire to secure by Letters Patent is:

1. In the feeding of sheets, the method of reducing those errors in registration that arise from dimensional changes in the sheets which comprises providing the sheets each with lay marks in predetermined positions with respect to a predetermined registration point intermediate the edges of the sheet, automatically controlling the advance of successive sheets photoelectrically by at least one of said lay marks to locate the registration point of the sheet in a fixed position with respect to the direction of advance of the sheets, rotating the sheet in its own plane, and automatically stopping the rotary motion of a sheet photoelectrically by another of said lay marks when the sheet is registered about its predetermined registration point.

2. In the feeding of sheets, the method of automatically registering successive sheets about similarly positioned registration points intermediate the edges of the several sheets which comprises providing each sheet with a plurality of lay marks in predetermined positions spaced from the registration point of that sheet, controlling movement of each sheet into laying-on position photoelectrically by at least one of said layv marks, rotating the sheet in its own plane, and arresting the rotation of each sheet photoelectrically in accordance with another of said lay marks.

3. In color printing, the method of feeding sheets from a pile to laying-on position for engagement by the grippers of an impression cylinder which comprises providing each sheet adjacent the border thereof with lay marks in predetermined positions with respect to a registration point Within the area to be printed, controlling the advance of the successive sheets into layingon position photoelectrically by one of said lay marks, moving the sheet successively in two directions each at an angle to the direction of advance of the sheet, one of said movements being a rotation of the sheet in its own plane, and arresting each of said movements photoelectrically by other lay marks.

4. VIn colour printing, a method of feeding sheets in register to an impression cylinder, which comprises providing the sheets with lay marks arranged in two intersecting lines, said lines intersecting at a registration point centrally located on said sheets, and operating sheet-shifting and positioning means under the control of photosensitive devices influenced by the said lay marks.

5. A method of feeding sheets from a pile, which comprises effecting pre-registration of the sheets to at least one edge by mechanical means and thereafter automatically registering the sheets to lay marks thereon by the use of mechanism under the control of photo-sensitive devices arranged to be inuenced by the said lay marks.

6. A method of feeding sheets from a pile which comprises providing each sheet with three lay marks in two intersecting lines substantially at right angles to the edges of the sheet and intersecting at a registration point centrally located on said sheets, two of said lay marks being in one line transverse to the direction of travel of the sheet, and the third lay mark being arranged on a line in said direction of travel, and effecting automatic registration under the control of three photo-sensitive devices positioned for operation by the said lay marks.

'7. Apparatus for feeding sheets each provided with lay marks in predetermined positions with respect to a predetermined registration point intermediate the edges of the sheet, said apparatus comprising means for advancing a sheet into laying-on position, means for moving a sheet at an angle to the direction of its advance into laying-on position, and photo-sensitive devices responsive respectively to different lay marks for arresting the operation of said advancing means and said moving means when a sheet reaches a desired advanced position and a desired angularly moved position respectively.

8. Apparatus for feeding sheets each provided with a plurality of lay marks in predetermined positions with respect to a predetermined registration point intermediate the edges of the sheet, said apparatus comprising means for advancing a sheet towards laying-on position, photoelectric means controlled by one lay mark for arresting the operation of said advancing means, means for moving the sheet in succession in two directions at angles to the direction in which the sheet was advanced, one sheet moving means imparting a rotary motion to the sheet, and photoelectric means controlled by at least one other of said lay marks for arresting the operation of each of said sheet moving means.

9. Apparatus for feeding sheets each provided with a plurality of lay marks in predetermined position with respect to a preselected registration point intermediate the edges of the sheet, a sheet advancing and a pair of sheet moving means operative in succession to advance a sheet into laying-on position and then to impart movements to the sheet in directions at angles to the direction of the sheet advance, and photoelectric means controlled by said lay marks for arresting in succession the operation of said sheet advancing and said sheet moving means.

.10.;:Apparatus for feeding sheets each provided withaplurality of lay marks in predetermined positions vwith respect to a preselected registration point intermediate the edges of the sheet, said apparatus including sheet advancing means including a pair of photoelectric devices actuated by certain of said lay marks for advancing the sheets in succession and rotating them to bring a registration line through the preselected registration point into a predetermined position, means operative thereafter to move the sheet to bring another registration line through the preselected registration point into a predetermined position.

ll. Apparatus for feeding sheets provided with lay marks arranged in lines intersecting at a predetermined point intermediate the edges of the sheet, said apparatus comprising feeding means including photoelectric devices responsive to certain of said lay marks for advancing the sheets successively into laying-on position, and means including a photosensitive device responsivevto another lay mark for rotating a sheet upon its arrival at laying-on position to eiect registration of the sheet at its said predetermined point.

12. Apparatus as claimed in claim 11, in combination with means preventing operation of said rotating means prior to an actuation of said feeding means to advance a sheet into laying-on position.

13. Apparatus for feeding sheets provided with lay marks arranged on lines intersecting at a predetermined point intermediate the edges of the sheet about which any error in registration is to be distributed, comprising photosensitive devices positioned to be influenced by said lay marks when a sheet is in registration position, sheetshifting and positioning mechanism, and means including electrical relays underthe control of said photosensitive devices for controlling the operation of said sheet-shifting and positioning mechanism to register the sheet with reference to the said predetermined point on the sheet.

14. Apparatus for feeding sheets each provided with a plurality of lay marks in predetermined positions with respect to a preselected registration point centrally located on the sheet, said apparatus comprising three photosensitive devices positioned to be influenced by said lay marks, means for feeding a. sheet towards layingon position, means for rotating a sheet upon its arrival in laying-on position, sheet moving means for moving a sheet into fully registered position, timing means operative to energize said sheet feeding means and thereafter in succession said sheet rotating and sheet moving means, and means controlled by said photosensitive devices for arresting in succession the operation of said sheet feeding means, said sheet rotating means and said sheet moving means.

l5. Apparatus as claimed in claim 14, wherein the means controlled by the respective photosensitive devices includes electrical relays and the circuit of the electrical relay of the third photosensitive device which controls the sheet moving means is normally open, in combination with relay means in the circuits controlled by the other photosensitive devices for closing the relay circuit of the third device upon the energization of said other devices.

16. Apparatus for feeding sheets provided with lay marks arranged on lines transverse to the feed movement of the sheet and to the transverse lay of the sheet, said lines intersecting at a predetermined point on the sheet about which any error in registration is to be distributed, said apparatus comprising three photosensitive devices two of which are positioned to be influenced by the lay marks located on a line transverse to the feed movement of the sheet, the third of said devices being positioned to be influenced by a lay mark arranged on a line transverse to the direction of transverse lay movement of the sheet, means controlled by said two first-mentioned devices for positioning the sheet with regard to travel towards the laying-on position, and means controlled by said third device for moving and positioning the sheet laterally.

17. Apparatus as claimed in claim 16, wherein the means controlled by said third device includes a transverse lay b`ar; and the means controlled by the other devices comprises a pair of grippers independently controlled by the first two devices for clamping a sheet to said transverse lay bar.

18. Apparatus as claimed in claim 16, wherein the means controlled by said third device includes a transverse lay bar, a cam for controlling the movement of said transverse lay bar, and electromagnetic means energized by said third device for arresting the cam-controlled movement of said transverse lay bar.

19. Apparatus for feeding sheets into a layingon position, said sheets having lay marks for registration of the sheets about predetermined registration points intermediate the edges of the several sheets, said apparatus comprising feeding means and transverse displacing means operable in timed sequential relation to advance a sheet into laying-on position and to move a sheet into registration after arrival at laying-on position, means including photosensitive devices responsive to different lay marks for gripping a sheet upon arrival at the desired laying-on position and registration position respectively, and means operable in timed relation to said feeding means and said moving means to release said gripping means.

20. In printing apparatus, the combination With a relay for controlling the energization of the driving motor of a printing press, of means for feeding to the printing press sheets having lay marks for determining the registration thereof, photosensitive means positioned for energization by said lay marks when a sheet is properly registered, relay circuits energized by said photosensitive means for controlling said feeding means, said relay for controlling the driving motor being included in one of said relay circuits, whereby energization of said printing press motor is dependent upon the proper registration of a sheet to be printed.

21. In printing apparatus as claimed in claim 20, the combination with a source of current, and switch means for energizing said motor-controlling relay and said relay circuits in predetermined timed relation.

22. In apparatus for feeding into laying-on position sheets having lay marks for determining the registration of the sheets about a predetermined point on the sheets, the combination with means for advancing the sheets to laying-on position, a transverse lay bar, photoelectric means responsive to certain of said lay marks for clamp ing a sheet to said lay bar upon arrival at layingon position, a spring tending to move said lay bar in one direction, a cam and lever mechanism for determining the displacement of said lay bar by said spring, photoelectric means controlled by another lay mark and means energized thereby for arresting the movement of said lay bar by said spring, whereby slack is developed in said lever mechanism upon the continued movement of said cam, and a switch operable by slack in said lever mechanism to close a holding circuit for said movement arresting means, whereby said holding circuit is opened by said switch only when the slack is eliminated from said lever mechanism upon the reverse movement of the cam.

REGIN ALD FREDERICK GEORGE HOLNESS l ll 

